Greg,
Bummer on the TV problem. Indeed it could be the main board or the display panel. It could also be in the cabling between them too, but that is probably less likely (worth checking if you haven't though). You could try Shopjimmy.com for a replacement board to see if you want to try to shotgun a part into it. May be a bit pricy for a whim though.
The funny thing is that I have run nothing but Samsung computer monitors since about 1998 and they have been almost 100% perfect. I did repair two LCD's with fluorescent backlights, one was bad caps and the other had a bad inverter transformer. I have been looking at buying a new 4K TV and all I have looked at have been Samsung models. All brands will have occasional failures, not sure Samsung is worse then any of the rest.
I wouldn't consider a Samsung appliance, or phone for that matter. Although the phone choice is because I don't want a phone running a 'free' OS...